How does the BCM work on a PassLock?
How does the BCM work on a PassLock?
The BCM communicates the signal digitally to the PCM for verification. If the signal is correct, it will enable vehicle start. Voltage to the lock cylinder case sensor is provided by the BCM. The BCM measures the voltage on the sensor circuit.
How does the voltage work on a PassLock sensor?
The voltage value indicates whether the Passlock sensor has been activated by the rotation of the lock cylinder or whether the lock cylinder has been removed, indicating a tamper situation. The BCM checks the voltage and compares it to a programmed and learned value to see if it is valid.
Why does my car not start with the correct PassLock password?
If the voltage from the lock cylinder sensor is incorrect or the voltage indicates a tamper condition, the BCM will not send the correct password to the PCM and the vehicle won’t start. This part can be confusing because the PCM will always allow the engine to crank and start regardless of the condition of the Passlock system.
What should I do if my PassLock fails?
The sensor in the lock cylinder case is the most common failure point, along with wiring harness issues between the lock cylinder case and the connector at the bottom of the steering column. You can replace the lock cylinder case yourself and perform a 30-minute relearn procedure without the use of a scan tool.
What happens if the BCM does not send the password?
The voltage matches, the BCM sends a digital message containing a password to the PCM. If the voltage from the lock cylinder sensor is incorrect or the voltage indicates a tamper condition, the BCM will not send the correct password to the PCM and the vehicle won’t start.
The voltage value indicates whether the Passlock sensor has been activated by the rotation of the lock cylinder or whether the lock cylinder has been removed, indicating a tamper situation. The BCM checks the voltage and compares it to a programmed and learned value to see if it is valid.
What happens if you give the PCM the wrong password?
However, if the PCM receives the wrong password from the BCM or no password, it will still allow engine cranking but will shut down the fuel injectors and stall the engine. The fuel injectors will remain off for 10-minutes even if the lock cylinder is turned from RUN to OFF and a restart is tried.
Why does my BCM say no start?
A “no crank” or no start status on the engine may be observed when the BCM malfunctions. This is primarily because of the BCM’s miscommunication with other control systems of the vehicle.
